After the contract is let and the actual construction is commenced, if the work is being done with a floating dredge the superintendent in charge of construction shall notify any railroad company the right of way of which is to be crossed by the work of the probable time at which the contractor will be ready to enter upon the right of way of the road and construct the work thereon. The railroad shall send a representative to view the ground with the superintendent of construction and arrange the exact time at which such work can be most conveniently done.